#!/usr/bin/perl -Tw
#
#   $Id: nets.cgi,v 1.12 2007/01/17 01:23:02 syzdek Exp $
#
#   Network Calculator
#   Copyright (C) 2006 David M. Syzdek <syzdek@gmail.com>
#
#   This program is free software; you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation; either version 2 of the License, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program; if not, write to the Free Software
#   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
#   nets.cgi - calculates common network addresses from multiple IP addresses
#              Can be run from commandline or as a CGI.
#

# +-=-=-=-=-=-+
# |           |
# |  Headers  |
# |           |
# +-=-=-=-=-=-+

use strict;

$|++;

our $PROGRAM_NAME       = 'nets.pl';
our $VERSION            = '0.02';
our $DESCRIPTION        = 'Network Calculator';
our $AUTHOR             = 'David Syzdek "syzdek@gmail.com"';

$ENV{'WHOIS'}           = 'http://ws.arin.net/whois/?queryinput=';


# +-=-=-=-=-=-=-=+
# |              |
# |  Prototypes  |
# |              |
# +-=-=-=-=-=-=-=+

sub button($$;$);       # displays button
sub cmdline(@);         # parses commandline
sub calc_ips(@);        # generates list of IP addresses
sub calc_network(@);    # calculates nework address of smallest network
sub display($$$);       # displays network data
sub form(@);            # displays form
sub ip2str($);          # converts IP to string
sub sourcedump();       # displays source
sub usage();            # prints usssage
sub version();          # prints version

sub main(@);


# +-=-=-=-=-=-=-+
# |             |
# |  Functions  |
# |             |
# +-=-=-=-=-=-=-+

# displays button
sub button($$;$)
{
   # grabs passed args
   my $link	= shift;
   my $title	= shift;
   my $hint	= shift || $title;

   # prints button
   printf("<table class=button>");
   printf("<tr class=button>");
   printf("<td class=button>");
   printf("<a class=button title=\"%s\" href=\"%s\" onmouseover=\"window.status = '%s';return true;\" onmouseout=\"window.status = '';return true;\">", $hint, $link, $hint);
   printf("&nbsp; %s &nbsp;", $title);
   printf("</a>");
   printf("</td>");
   printf("</tr>");
   printf("</table>");

   # ends function
   return(0);
};


# parses commandline
sub cmdline(@)
{
   # grabs passed args
   my @argv	= @_;

   # declares local vars
   my $arg;
   my $buff;
   my $name;
   my $pair;
   my $value;
   my @list;
   my @pairs;
   my @timestamp;

   # creates headers
   if (! defined($ENV{'QUERY_STRING'}))
   {
      foreach $arg (@argv)
      {
         if ($arg eq '--help')
         {
            usage();
            exit(0);
         } elsif ($arg eq '--version') {
            version();
            exit(0);
         };
      };
      if (@argv < 1)
      {
         usage();
         exit(0);
      };
      return(calc_ips(@argv));
   };

   # checks path INFO
   if ($ENV{'PATH_INFO'})
   {
      if ($ENV{'PATH_INFO'} eq "/" . $PROGRAM_NAME)
      {
         sourcedump();
         exit(0);
      } elsif ($ENV{'PATH_INFO'} eq "/--help") {
         printf("Content-type: text/html\n\n");
         help();
         exit(0);
      } elsif ($ENV{'PATH_INFO'} eq '/--version') {
         printf("Content-type: text/html\n\n");
         version();
         exit(0);
      };
   };
   if ($ENV{'QUERY_STRING'} eq "sourcedump")
   {
      sourcedump();
      exit(0);
   } elsif ($ENV{'QUERY_STRING'} eq "--help") {
      printf("Content-type: text/html\n\n");
      usage();
      exit(0);
   } elsif ($ENV{'QUERY_STRING'} eq "--version") {
      printf("Content-type: text/html\n\n");
      version();
      exit(0);
   };

   # prints headers
   printf("Content-type: text/html\n\n");

   # parses linked data
   $buff = $ENV{'QUERY_STRING'};
   @pairs = split(/&/, $buff);
   foreach $pair (@pairs)
   {
      ($name, $value) = split(/=/, $pair);
      if ($name eq 'ip')
      {
         $value =~ tr/+/ /;
         $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
         #if ($value =~ /^([\d]+\.[\d]+\.[\d]+\.[\d]+[ ]{0,1})+$/)
         if ($value =~ /^([\d]+\.[\d]+\.[\d]+\.[\d]+)$/)
         {
            $list[@list] = $1;
            #return(calc_ips(@list));
         };
      } elsif ($name eq 'noform') {
         if ($value eq 'true')
         {
            $ENV{'NOFORM'} = 'true';
         };
      } elsif ($name eq 'nowhois') {
         if ($value eq 'true')
         {
            $ENV{'NOWHOIS'} = 'true';
         };
      } elsif ($name eq 'noopts') {
         if ($value eq 'true')
         {
            $ENV{'NOOPTS'} = 'true';
         };
      };
   };

   # sets default IP addresses
   if (@list eq 0)
   {
      # sets 192.168.X.X addresses using Month, Day, hour, and minute
      @timestamp = localtime(time);
      $list[@list] = (0xc0a8 << 16) | (($timestamp[4] + 1) << 8) | ($timestamp[3]);
      $list[@list] = (0xc0a8 << 16) | (($timestamp[2]) << 8) | ($timestamp[1]);
      $ENV{'QUERY_STRING'} = 'ip=';
   };

   # ends function
   return(calc_ips(@list));
};


# generates list of IP addresses
sub calc_ips(@)
{
   # grabs passed args
   my @ips	= @_;

   # declares local vars
   my $count;
   my @list;

   # creates list of IP addresses
   for($count = 0; $count < @ips; $count++)
   {
      if ($ips[$count] =~ /^([\d]+)\.([\d]+)\.([\d]+)\.([\d]+)$/)
      {
         $list[@list] = (($1 & 0xff) << 24) | (($2 & 0xff) << 16) | (($3 & 0xff) << 8) | ($4 & 0xff);
      } elsif ($ips[$count] =~ /^([\d]+)$/) {
         $list[@list] = $1;
      };
   };

   # ends function
   return(@list);
};


# calculates nework address of smallest network
sub calc_network(@)
{
   # grabs passed args
   my @list	= @_;

   # declares local vars
   my $ip;
   my $net;
   my $mask;
   my $cidr;

   # sets preliminary values
   $net = 0xFFFFFFFF;
   $mask = 0;
   $cidr = 33;

   # loops through network data
   while ((! $mask)&&($net))
   {
      $mask = $net;
      foreach $ip (@list)
      {
         if (($ip & $mask) != ($list[0] & $mask))
         {
            $mask = 0;
         };
      };
      $net = $net << 1;
      $cidr--;
   };

   # ends function
   return($mask, $cidr);
};


# displays network data
sub display($$$)
{
   # grabs passed args
   my $mask	= shift;
   my $cidr	= shift;
   my $ip	= shift;

   # declares local vars
   my $net;

   # prints header
   if ($ENV{'QUERY_STRING'})
   {
      printf("<table>\n");
      printf("   <tr><td align=center colspan=6><font size=+1><b>Common Networks</b></font></td></tr>\n");
      printf("   <tr>\n");
      printf("      <td align=left><b>&nbsp;&nbsp;Network&nbsp;&nbsp;</b></td>\n");
      printf("      <td align=left><b>&nbsp;&nbsp;CIDR&nbsp;&nbsp;</b></td>\n");
      printf("      <td align=left><b>&nbsp;&nbsp;Netmask (hex)&nbsp;&nbsp;</b></td>\n");
      printf("      <td align=left><b>&nbsp;&nbsp;Netmask (octets)&nbsp;&nbsp;</b></td>\n");
      printf("      <td align=left><b>&nbsp;&nbsp;Broadcast&nbsp;&nbsp;</b></td>\n");
      printf("      <td align=left><b>&nbsp;&nbsp;IP Count&nbsp;&nbsp;</b></td>\n");
      printf("   </tr>\n");
   } else {
      printf("%-16s %-4s %-11s %-16s %-16s %s\n", "Network", "CIDR", "Netmask", "Netmask", "Broadcast", "IP Count");
   };

   # prints data
   while($cidr > 0)
   {
      $net = $mask & $ip;
      if ($ENV{'QUERY_STRING'})
      {
         printf("   <tr>\n");
         if ($ENV{'NOWHOIS'})
         {
            printf("      <td align=left>&nbsp;&nbsp;%s&nbsp;&nbsp;</td>\n", ip2str($net));
         } else {
            printf("      <td align=left>&nbsp;&nbsp;<a href=%s%s>%s</a>&nbsp;&nbsp;</td>\n", $ENV{'WHOIS'}, ip2str($net), ip2str($net));
         };
         printf("      <td align=left>&nbsp;&nbsp;%s&nbsp;&nbsp;</td>\n", $cidr);
         printf("      <td align=left>&nbsp;&nbsp;0x%08X&nbsp;&nbsp;</td>\n", $mask);
         printf("      <td align=left>&nbsp;&nbsp;%s&nbsp;&nbsp;</td>\n", ip2str($mask));
         if ($cidr == 32)
         {
            printf("      <td align=left>&nbsp;&nbsp;%s&nbsp;&nbsp;</td>\n", ip2str($net));
            printf("      <td align=left>&nbsp;&nbsp;%s&nbsp;&nbsp;</td>\n", 1);
         } else {
            printf("      <td align=left>&nbsp;&nbsp;%s&nbsp;&nbsp;</td>\n", ip2str( (0xFFFFFFFF>>$cidr)|$net  ));
            printf("      <td align=left>&nbsp;&nbsp;%s&nbsp;&nbsp;</td>\n", (0xFFFFFFFF>>($cidr))+1);
         };
         printf("   </tr>\n");
      } else {
         if ($cidr == 32)
         {
            printf("%-16s %-4s 0x%08X  %-16s %-16s %s\n", ip2str($net), $cidr, $mask, ip2str($mask), ip2str($net), 1);
         } else {
            printf("%-16s %-4s 0x%08X  %-16s %-16s %s\n", ip2str($net), $cidr, $mask, ip2str($mask), ip2str((0xFFFFFFFF>>$cidr)|$net), (0xFFFFFFFF>>($cidr))+1);
         };
      };
      $mask = $mask << 1;
      $cidr--;
   };

   # prints last network
   if ($ENV{'QUERY_STRING'})
   {
      printf("   <tr>\n");
      printf("      <td align=left>&nbsp;&nbsp;0.0.0.0&nbsp;&nbsp;</td>\n");
      printf("      <td align=left>&nbsp;&nbsp;0&nbsp;&nbsp;</td>\n");
      printf("      <td align=left>&nbsp;&nbsp;0x00000000&nbsp;&nbsp;</td>\n");
      printf("      <td align=left>&nbsp;&nbsp;0.0.0.0&nbsp;&nbsp;</td>\n");
      printf("      <td align=left>&nbsp;&nbsp;255.255.255.255&nbsp;&nbsp;</td>\n");
      printf("      <td align=left>&nbsp;&nbsp;%s&nbsp;&nbsp;</td>\n", 0xFFFFFFFF);
   } else {
      printf("%-16s %-4s 0x%08X  %-16s %-16s %s\n", "0.0.0.0", 0, 0, "0.0.0.0", "255.255.255.255", 0xFFFFFFFF);
   };

   # prints tailer
   if ($ENV{'QUERY_STRING'})
   {
      printf("</table>\n");
   };

   #printf("network: %u.%u.%u.%u\n", ($mask >> 24)&0xFF, ($mask>>16)&0xFF, ($mask>>8)&0xFF, $mask&0xFF);

   # ends function
   return(0);
};


# displays form
sub form(@)
{
   # grabs passed args
   my @list	= @_;

   # declares local vars
   my $ip1;
   my $ip2;

   # checks for CGI
   if ((!defined($ENV{'QUERY_STRING'})) || ($ENV{'NOFORM'}))
   {
      return(0);
   };

   #  checks default
   if (@list < 1)
   {
      $list[@list] = (192<<24) | (168<<16) | (0<<8) | 1;
   };

   # sets first and last IP
   @list = sort(@list);
   $ip1 = $list[0];
   if (@list > 1)
   {
      $ip2 = $list[@list - 1];
   };

   # prints form
   printf("<p><a href=?--version><font size=+1>Network Calculator</font></a></p>\n");
   printf("<form method=link>\n");
   printf("   IP address: <input type=text name=ip value=\"%s\"><br>\n", ip2str($ip1));
   if ($ip2)
   {
      printf("   IP address: <input type=text name=ip value=\"%s\"><br>\n", ip2str($ip2));
   } else {
      printf("   IP address: <input type=text name=ip><br>\n");
   };
   if ($ENV{'NOOPTS'})
   {
      printf("   <input type=hidden name=noopts value=true>\n");
   } else {
      if ($ENV{'NOWHOIS'})
      {
         printf("   <input type=checkbox name=nowhois value=true checked> Hide Whois links<br>\n");
      } else {
         printf("   <input type=checkbox name=nowhois value=true> Hide Whois links<br>\n");
      };
   };
   printf("   <br>\n");
   printf("   <input type=submit value=\"Calculate Networks\">\n");
   printf("</form>\n");
   
   # ends function
   return(0);
};


# converts IP to string
sub ip2str($)
{
   my $ip = shift;
   my $str;
   $str = ($ip>>24) & 0xFF;
   $str = $str . '.';
   $str = $str . (($ip>>16) & 0xFF);
   $str = $str . '.';
   $str = $str . (($ip>>8) & 0xFF);
   $str = $str . '.';
   $str = $str . ($ip & 0xFF);
   return($str);
};


# displays source
sub sourcedump()
{
   printf("Content-type: text/plain\n\n");
   if (! $ENV{'SCRIPT_FILENAME'})
   {
      return(0);
   };
   if (! open(FILE, "$ENV{'SCRIPT_FILENAME'}"))
   {
      return(0);
   };
   while(<FILE>)
   {
      printf("%s", $_);
   };
   close(FILE);
   return(0);
};


# prints usssage
sub usage()
{
   if ($ENV{'QUERY_STRING'})
   {
      printf("<table><tr><td align=left><pre>\n");
   };
   printf("Command Line Usage: %s [options] address [address]\n", $PROGRAM_NAME);
   printf("      --help            print this help and exit\n");
   printf("      --version         print version number and exit\n");
   printf("CGI Usage:\n");
   printf("  ip=x.x.x.x            first IP address used to calculate IP netblock\n");
   printf("  ip=x.x.x.x            second IP address used to calculate IP netblock\n");
   printf("  noform=true           boolean value causes CGI to not print form\n");
   printf("  nowhois=true          boolean value causes CGI to not print links to whois\n");
   printf("  sourcedump            displays source code\n");
   if ($AUTHOR)
   {
      printf("\n");
      printf("Report bugs to %s.\n", $AUTHOR);
   };
   if ($ENV{'QUERY_STRING'})
   {
      printf("</pre></td></tr></table><br>\n");
      printf("<a href=?--version>Version Information</a>\n");
      printf("&nbsp;&nbsp;&nbsp;&nbsp;\n");
      printf("<a href=?>Use Calculator</a>\n");
      if (($ENV{'QUERY_STRING'})&&($ENV{'SCRIPT_NAME'})&&($ENV{'SERVER_PROTOCOL'}))
      {
         printf("<br>\n");
         printf("<p><a href=%s/%s>Source Code</a></p>\n", $ENV{'SCRIPT_NAME'}, $PROGRAM_NAME);
      };
   };
   return;
};


# prints version
sub version()
{
   if ($ENV{'QUERY_STRING'})
   {
      printf("<table><tr><td align=left><pre>\n");
   };
   printf("%s (%s) %s\n", $PROGRAM_NAME, $DESCRIPTION, $VERSION);
   printf("Written by %s.\n", $AUTHOR);
   printf("\n");
   printf("Copyright 2006 (c) %s\n", $AUTHOR);
   printf("This is free software; see the source for copying conditions.  There is NO\n");
   printf("warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n");
   if ($ENV{'QUERY_STRING'})
   {
      printf("</pre></td></tr></table><br>\n");
      printf("<a href=?--help>Help Information</a>\n");
      printf("&nbsp;&nbsp;&nbsp;&nbsp;\n");
      printf("<a href=?>Use Calculator</a>\n");
      if (($ENV{'QUERY_STRING'})&&($ENV{'SCRIPT_NAME'})&&($ENV{'SERVER_PROTOCOL'}))
      {
         printf("<br>\n");
         printf("<p><a href=%s/%s>Source Code</a></p>\n", $ENV{'SCRIPT_NAME'}, $PROGRAM_NAME);
      };
   };
   return;
};


# +-=-=-=-=-=-=-=-=-+
# |                 |
# |  Main  Section  |
# |                 |
# +-=-=-=-=-=-=-=-=-+
sub main(@)
{

   # grabs passed args
   my @argv	= @_;

   # declares local vars
   my $cidr;
   my $mask;
   my @list;

   @list = cmdline(@ARGV);

   # prints form
   form(@list);

   # processes networks
   if (@list > 0)
   {
      # determines Network address
      ($mask, $cidr) = calc_network(@list);

      # displays data
      display($mask, $cidr, $list[0]);
   };

   # show source code
   if (($ENV{'QUERY_STRING'})&&($ENV{'SCRIPT_NAME'})&&($ENV{'SERVER_PROTOCOL'}))
   {
      printf("<p><a href=%s/%s>Source Code</a></p>\n", $ENV{'SCRIPT_NAME'}, $PROGRAM_NAME);
   };

   # ends function
   return(0);
};
exit(main(@ARGV));

# ends function